Liquid gauge



J. D. DURANT LIQUID GAUGE Aug, 14, 1934.

Filed May 9, 1932 2 Sheets-Sheet l ORNEY Aug. 14-, 1934. J DURANT 1,969,783

LIQUID GAUGE Filed May 9, 1932 2 Sheets-Sheet 2 INVENTO? A ORNEY Patented Aug. 14, 1934 1,969,783 n w GAUGE John D. Durant, Detroit, Mich. Application 'May 9,1932, Serial No. 610,031

8 Claims.

. This invention relates to liquid gages of the hydrostatic type and particularly such as are employed on motor vehicles.

'Heretofore, in commercial forms of gages of this type, it has been found necessary to provide some special means for forcing or introducing air into the bell at the lower end of the :gage line, for so-called (rectifying purposes.

One of the special objects of this invention is to eliminate the means for forcing :or int-roducing air into :the bell of the gage line and hence to avoid such expense and simplify the structure.

Other objects are to generally improve the construction and operation of gages of the type indicated and to reduce the cost of manufacture and maintenance.

Further objects and the :novel features of construction, combinations and relations .of parts by which the objects are attained will appear from the following specification.

The drawings accompanying and .forming part of the'zspecification illustrate certain practical embodiments of the invention, but it is :to,be understood that the. structure may be rmodified as regards these particular illustrations all within 7 :the intent and ioroad scope of the claims hereinai-ter.

Fig. 1 is aibroken perspective view illustrating the application of the invention to a gasoline tank of an automobile.

Fig. 2 is an enlarged broken and "part sectional view of the so-called 'tank .nnit.

' Fig. :3 is .a broken'sectional view of the gage unit of :the invention.

Fig. 4 is a further-enlarged bottom plan view of the air bell structure shown in, 2..

Fig.6 is an enlarged sectional (detail of one of the :air separators used in the gage line.-

Fig. 6'is a broken :andlpart. sectional .ViBWwOf the invention as embodieldin the'form of an :oil gage for an engine.

Fig. 7 is an'enlarged'tbroken sectional detail of the air bells employed in the latter form of the invention.

InFig. l, the gasoline tank of an automobile is indicated at '11 having a liquid fuel 'withdrawing line '12 entered therein and connected with a pump 13. At '14, the indicatingdevice or gage unit is shown -.subjected to the'pressure of liquid within the tank through a pressureline 15 terminating in a so called air bell, icopen to the liquid near the bottom of the tank.

The air "bell is shown inFigs; 2 and a4 as-havin a relatively fine mesh wire screen 15!. set lupinto the mouth of the :same against a conical partition 2L8, .secur-edin the lower end portion of the bell and having a center opening :19, communicating with the pressure line 15.. The screen is shown foldedon radial lines .as at 20, Fig. 4, to form a series of radial webs with deep interstices between the same and leaving a clear center portion 21 about the central opening in the generally horizontal partition .18. This screen serves as an air collector or air separator for catching and releas- 66 ing impounded air from-the more or less aerated liquid in the tank.

The extent to which the screen projects below the bell and the fineness of the mesh may vary with different liquids. For gasoline a mesh of 70 about 80 to the inch and a projection in approximately the proportion shown in Fig. 2 have been found practical. The gasoline as it washes through the screen leaves a certain amount of the air particles therein caught in the mesh of the screen .and this air in the movements of the vehicle is shaken loose and by natural buoyancy finds its way .up into the hell. I The action is thus that of an .air collector extracting air from the liquid below the bell :and'wi-thout the :use of any force or liquid flow for introducing or pushing the air up into the bell.

As a matter of practical convenience, the suction line l2..of the pump is shown as carried by the same top plate '22, which supports the air 35 chamber so that the mounting of this plate in the top of the tank serves for positioning both the suction line and the gage line in the tank, butas the suction line has-no connection with the operation of the gage, it may be placed in any wholly separated relation.

The air bubbles may Joe threaded up into the gage line sby'hollow conical separators 23, Figs.

'2, 4 and 5, perforated at the topat 24 for upward release of air'and externally 'fiutedor grooved 5 .at .25 for backward draining "of the liquid, one such separator being shown located in the partition opening -19 and two others being indicated the upper and intermediate portions of the pipe 15, Fig. 2. g

The indicator or gage'instrument, is shown in Figs. 1; .3 and 6 as a U tube for holding a quantity of indicating liquid and as made .up of a section of tubing .26 threaded .at its upper end at 27 for thecoupli-ng 28 of the gage line and thinned and reduced at i-tslower endat 29;, the reduced thinned portion being doubled to form the bend of. the U tube and flanged at the top at 30, to provide a seat for the transparent visible portion 31.- The heavier, larger rear portion of the tube is shown embedded in the lugs 32, 33 of the cast metal base piece 34 and the thinned upwardly extending forward portion of this tube is shown embedded in the forwardly extending lug 35 of said base piece. This forward lug is illustrated as socketed at 36 for the lower end of the glass tubing and the upper end of such tubing is shown as held in the forwardly projecting lug 3'? of the base piece by means of the hollow screw plug 38 entered in the screw seat 39 in said lug and enclosing the neck 40 of a cupped flange member 41 seated over the upper end of the tube. Gaskets 42 and 43 are shown interposed between the ends of the tube and the tubing flanges 41 and 30. The screw plug 38 is shown as slotted at 44 to receive a spanner or similar tool for turning the plug down tightly in its seat. The tubing may be knurled or roughened as at 45, where the lugs are cast about the same, as indicated in Fig. 6.

The extension tubing 40 at the upper end of the gage glass is used in Figs. 1 and 3 as a vent and is shown as having a goose neck section 46 coupled in the upper end of the same to relieve pressure on the forward side of the liquid column and opening downward to prevent entrance of moisture.

-To save any indicating liquid which might be accidentally blown out through the goose neck, a catch cup 4? may be removably engaged over the end of the vent tube as by a bayonet catch 48, said cup being vented in one or more places .as at 49, beneath the overstanding flange 50 or top of the same. In addition to saving any drip or overflow from the U tube, this cup prevents any indicating liquid from dripping down and discol- Oring the scale or other portions of the instrument. The indicating liquid caught in the cup may be restored to the system by slipping the cup oif the end of the goose neck and pouring the saved liquid back into the upper end of the U tube, when the latter is opened up by removal 1 the coupling at 28. 1

The gage glass is sealed and cushioned at its opposite ends by the gaskets 42, 43 and the upper flange 41 serves as a Washer for preventing the tube from turning as the securing plug 44 is screwed down in the socket 39. Thevent tube may be turned to stand in different angular relations, when the screw plug is loosened and the plug when set up tight serves to hold the goose neck in any desired relation.

The construction shown in Figs. 6 and '7 is designed for-registering the oil in the oil pan of an engine or the like. In this instance, two tank units are employed, one located at the'upper oil level 51 of the oil pan 52 and the other disposed at the lower oil level 53, the latter being connected by the pressure line 54 with the back leg of the U tube and the formerbeing connected by a pressure line 55 with the front leg of the instrument. The upper unit is thus connected to check the rise of the gage liquid if an excess of oil is put in the crank case, holding the gage to the high level indication and preventing the gage liquid being forced up into the piping. Theunits are alike except that the upper bell 56 is shown as having the tubing 54 from the lower bell 57 passing upwardly through the same, so that the two are tied together in vertical alignment, one over the other.

These air bells are generally the same as those heretofore described including the substantially horizontal partition 18, centrally perforated at 19 and the dependent skirt or'flange of air extracting screening 17. The latter may be crimped or crinkled to provide greater area and air catching interstices, or may be a plain cylindrical skirt and the mesh may be somewhat coarser than used for gasoline and lighter liquids.

A feature of the oil gage air bells is that they are shown with bulging overstanding rims 58, having air escape openings 59 in the rounded undersides of the same. These enable excess air to escape without tearing or breaking the meniscus at the mouth of the bell.

Bent or twisted wires, such as shown at 60 may be placed in the pressure lines 54, 55 above the air bells to drain back oil to prevent it from creeping up into these lines.

In all the several forms herein disclosed, the need for any special air injecting or air introducingmeans is avoided by simply having'a collector which will extract the air impounded in the liquid surging or washing back and forth in the mouth of the bell. The perforate, mesh or reticulate structure of the air absorber or collector offers practically no opposition to the flow of liquid, since it does not act as a bafile or deflector for the liquid and consequently the tank unit can be made of light inexpensive materials. This air absorption device may be carried by either the gage line ortlie tank, or partly by both. The, screen, at the upper end may be rigidly fastened in the mouth ofthe bell, as by soldering or the like, leaving the portions extending below the bell as resilient flexible extensions, which can yield one way or the other, for example if the unit be set down too far and actually against the bottom of the tank. This eliminates any need for great accuracy in fitting the unit down in the tank and the screen serves as a resilient buffer preventing the mouth of the bell being set too close to the bottom of the tank. The engagement of this resilient member with the bottom of the tank further serves to brace the unit inthe tank. If the suction line is carried by the tank unit as in Fig. 2, the lower end of the same should be short of the lower edge of the screen, so that if contactof the screen is made with the bottom of the tank, the suction line will not be closed off.

The crumpled or folded screen presents a greater surfaceto the moving gasoline than a plain or straight vertical wall, intercepting the air in the gasoline to an accordingly greater extent. This foraminous air collector, forliquids such as gasoline, should extend an appreciable or considerable distance down below the mouth of the bell and should have a vertical extent equal to the full diameter ofthe mouth of the bell. In addition to extracting air impounded in the liquid,

the screen may have a carbureting action on gasoline or the like, the flow through the screen breaking the liquid up into a great number of fine jets and having a tendency to efiect separation of the lighter components from heavier portions of the liquid. Gas'thus "liberated by the jetting action of flow through the screen has a tendency to rise and hence escape passing out through the screen at the other side. Also, in-this rising action, the small bubbles have a tendency to collect and cohere and thus by increase in size to become trapped in the center space of the screen beneath the air bell. The air collector is not a strainer for the gasoline taken up by the pump, but doesnot interfere with the somewhat customary'use of a strainer over the pump inlet tube;

A number of different embodiments of the invention have been disclosed herein, suflicient it is believed; to make it clear that the actual physical iso the broad scope of the claims. It will be understood also, that the terms employed herein have been used in a descriptive rather. than in a limiting' sense, except possibly for limitations that may be imposed by the state of the prior art.

What is claimed is:

l. A liquid gage of the character set forth, comprising in combination, a gage line entered in the liquid to be measured and having a bell at the inner end of the same, a gage instrument connected with the outer end of said gage line, a foraminous air separator at the inner end of the gage line and consisting of a fine mesh Wire screen bent upon itself in a plurality of folds located within the confines of the bell to cause liquid sloshing therethrough to liberate a greater amount of air within the bell.

2. In combination with a gage for indicating liquid values, a tube connected at its upper end with said gage, an air bell on the lower end of said tube, reticulated air separating means extending downward from the rim of said air bell and consisting of a wire screen folded upon itself and having the folds of the same located within the mouth of the bell.

3. A tank unit of the character. disclosed, comprising a pressure line adapted for connection with a liquid indicating gage and provided with an air bell at the lower end of the same and an air separating screen arranged in folds within the mouth of said air bell.

4. In combination with a liquid indicating instrument, a pressure line connected with said instrument and an air bell on the end of said pressure line, said air bell having outstanding bulging sides and an air escape opening or openings in the underneath rounded portions of said outstanding bulging sides.

5. In combination with a liquid indicating instrument, a pressure line connected with said instrument and an air bell on the end of said pressure line, said air bell having outstanding bulging sides, an air escape opening or openings in the underneath rounded portions of said outstanding bulging sides and an air separating mesh associated with the mouth of said air bell.

6. A tank unit, comprising in combination, a pressure line for connection with a gage, said pressure line having an air bell at the lower end of the same, a transverse partition in the mouth of the air bell and provided with an opening therethrough, a hollow conical unit seated in said opening, said unit having its pointed end uppermost and pierced for passage of air and grooved in its side for flow back or liquid and air separating means associated with the mouth portion of the air bell.

7. A gage for gasoline tanks of automobiles and the like, comprising in combination with an indicating instrument, a pressure line connected with said instrument and adapted to extend down into the gasoline in the tank, said pressure line having a bell at the lower end of the same open to the pressure of gasoline within the tank and layers of foraminous material within said bell and extending downwardly from said level of pressure communication of the bell, said layers of foraminous material being disposed substantially vertically to jet the liquid flowing horizontally beneath and past the mouth of the bell in fine streams tending to release the lighter from the heavier components of the gasoline in the space within the bell inside the layers of foraminous material.

8. In a gage of the character disclosed,the combination of an indicator, a tube connected therewith at one end and a bell at the opposite end of the tube for immersion in the liquid and having a radially folded screen in the lower end of the same and disposed within the confines of the bell, the radial folds of the screen extending toward the center of the bell but leaving a clear space substantially in line with the tube.

JOHN D.. DURANT. 

